Omron CJ - 09-2009 Operation Manual page 66

CJ1-H and CJ1M CPU Unit Features
Convert between Floating
Point and Text String Data
Accurate Line
Approximations
Realtime Workpiece Data
Management
PID Autotuning
System Debugging
through Error Simulation
Program Simplification
with More Specific Basic
Instructions
Delayed Power OFF
Processing for Specified
Program Areas
Multiple Interlock
Instructions (MILH(517),
MILR(518), and MILC(519))
for Nested Interlocks
TIME-PROPORTIONAL
OUTPUT (TPO(685))
Instruction for Time-pro-
portional Operation with
Temperature Controllers
or Variable-duty Lighting/
Power Control
Symbol Time Comparison
Instructions for Easy
Calendar Timers
18
To display floating-point data on PTs, the CJ1-H CPU Units provide conver-
sion instructions from floating-point data to text strings (ASCII). Conversion
between ASCII and floating-point data is also possible so that ASCII data from
serial communications with measurement devices can be used in calcula-
tions.
Unsigned 16-bit binary/BCD data, signed 16/32-bit binary data, or floating-
point data can be used for line data, enabling precise (high data resolution)
conversions, such as from a level meter (mm) to tank capacity (l) based on the
shape of the tank.
When loading and unloading workpieces from conveyor lines, stack instruc-
tions can be used to manage workpiece information in realtime in table for-
mat.
Autotuning is now supported for PID constants with the PID CONTROL
instruction. The limit cycle method is used to ensure rapid autotuning. Very
effective for multiloop PID control.
A specified error status can be created with the FAL/FALS instructions. This
can be used effectively when depending systems. For example, errors can be
simulated to produce corresponding displays on a PT to confirm that the cor-
rect messages are being displayed.
Programs that use a high quantity of basic instructions can be simplified
though the use of differentiated forms of the LD NOT, AND NOT and OR NOT
instructions, and through the use of OUT, SET, and RSET instructions that
can manipulate individual bits in the DM or EM Area.
The DI and EI instructions can be used to disable interrupts during specific
portions of the program, for example, to prevent the power OFF interrupt from
being executed until a specific instruction has been executed.
These instruction enable easy creation of nested interlocks. For example, cre-
ate one interlock to control the entire program (e.g., for an emergency stop)
and then nest other interlocks for separate portions of the program (e.g., con-
veyor operation, alarms, etc.).
This instruction is used in combination with PID instructions to create a time-
proportional output based on the manipulated variable output by the PID
instruction. This enables easily connecting an SSR to a Transistor Output Unit
to achieve time-proportional operation of a Temperature Controller. Variable-
duty pulse outputs can also be created for lighting or power control.
Two times/dates can be compared to continue operation to the next instruction
in the ladder program rung when the results of comparison is true. Opposed
to normal comparison instructions, comparisons are by byte and the bytes
that are compared in the time/date data can be controlled. This enables com-
paring built-in clock data with set times/dates to easily create a calendar timer,
for example, on the hour (when the minutes is 0) or on a specific date each
year).
Section 1-3